报告题目：水中光致击穿效应多光子电离诱发机理研究
报告时间：元月5日下午2:30分
地 点：生命学院301会议室
报 告 人：梁晓轩
报告内容介绍：
Investigation of the wavelength dependence (725 – 1025 nm) of the threshold for nanosecond optical breakdown in water revealed steps consistent with breakdown initiation by multiphoton ionization, with an initiation energy of »6.6 eV. This value is considerably smaller than the autoionization threshold of »9.5 eV, which can be regarded as band gap relevant for avalanche ionization. Breakdown initiation likely occurs via excitation of a valence band electron into a solvated state, followed by rapid excitation into the conduction band. Based on these assumptions, the seed electron density required to initiate avalanche ionization was found to drop from 2.5´1015cm-3 at 725 nm to 1.1´1012cm-3 at 1025 nm. These results demand changes of future breakdown modeling for water including the use of a larger band gap than previously employed, the introduction of an intermediate energy level for initiation, and consideration of the wavelength dependence of seed electron density.
个人简介：
梁晓轩, 男, 1986年2月出生。2002年9月考入西安交通大学生物医学工程系，于2006年7月获工学学士学位。随后直接保送本校生物物理专业攻读博士学位。师从张镇西教授。从2007年10月开始，在国家留学基金委“国家建设高水平大学公派研究生项目”及国家自然科学基金“国际合作重点项目”资助下, 3次赴德国吕贝克大学生物医学研究所开展为期3年半的博士联合培养，2013年博士毕业。多次在SPIE举办的国际光学会议及中德生物医学光学研讨会上做口头报告。为Applied Physics B审稿人。现在主要研究方向为超快速激光诱发等离子体, 多光子物理, 空化气泡动力学, 激光纳米微手术。 | 
